Bathymetry of Lo`ihi volcano, just south of the
Big Island of Hawai`i.Stars represent
the locations of ocean-bottom seismometers deployed in September 2010.

Lō`ihi volcano has its summit
about a kilometer below sea level, 30 km south of the Big Island of
Hawai`i.This active submarine volcano
is the youngest expression of the Hawaiian hot spot and will one day be the
next island in the Hawaiian chain.Although the petrology, vent chemistry and morphology of Lō`ihi has been studied for decades, its earthquakes and
their relation to internal structure and eruptive processes remain poorly
understood.This is largely due to the
volcano’s location relative to the Big Island:Lō`ihi sits outside of the permanent seismic
network operated by the Hawaiian Volcano Observatory (HVO).Thus Lō`ihi
earthquakes are poorly located and only earthquakes over a substantial
magnitude (~1.7) are reliable recorded.

To
address this issue, researchers from WWU and the University of
Wisconsin—Madison are engaging in a study to investigate Lō`ihi
earthquakes with a network of ocean-bottom seismometers (OBS’s; see the figure
below).In this NSF-funded project, 12
OBS’s were deployed on and around the volcano in September 2010 and were
retrieved in July 2011.Data from this
project will help answer a large number of questions that remain about Lō`ihi.We hope to
investigate where Lō`ihi’s earthquakes occur relative
to its summit and rift zones.We hope to
determine whether submarine volcanoes exhibit the same types of earthquakes
(e.g. long-period events) that are observed on subaerial volcanoes, and how these
events are related to fluid flow in the volcanic
edifice.Seismic data from both Lō`ihi and the Big Island will be used to investigate Lō`ihi’s internal velocity structure and determine whether
the volcano has a permanent magma reservoir, where rift zones are located, and
where the boundary lies between Lō`ihi and its
neighboring volcanoes Mauna Loa and Kilauea.Other data collected on the deployment cruise include gravity and magnetics.Analysis
of these data will provide another view into Lō`ihi’s
internal structure and may help constrain the relationship between the young
seamount and the volcanoes that comprise the Big Island.